| 内容提要: |
A good quality cementing operation is important to exploit oil and gas resources. Therefore, cement additives are added to the oil well cement to enhance the comprehensive properties of cement paste in harsh environment. Among substantial cementing additives, dispersant is used to prevent cement particles from flocculating, which releases entrapped water and enhances the dispersion ability of cement paste. With the development of cement-based materials in cement industry, different types of dispersants with various dispersing capabilities have been widely applied, such as lignosulfate, polycondensate (PN) and the latest generation of polycarboxylate (PCE) dispersants. Extensive researches have been focused on the molecular design of PN and PCE dispersants in order to achieve excellent performance.
In spite of much effort in the molecular design of dispersants, there are still many discussions regarding the detailed working mechanism through which dispersants affect the dispersion behaviors and cement hydration. Therefore, this paper systematically investigated the application performance and working mechanism of two main types of oil-well dispersants designated by the code APC (amphoteric polycarboxylate-based) dispersant and SAF (sulfonated acetone formaldehyde polycondensate-based) dispersant. This study provides a theoretical foundation for the design of highly efficient dispersant systems and their practical applications in oil well cementing operations. |